Obstetrics Dr. Eman
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Induction &
Augmentation of
labour
Induction oflabour: Is a process where labour is initiated by artificial means
Augmentation of labour: Is the artificial stimulation of labour that has begun
spontaneously
Indication of IOL
Maternal:Fetoplacental
Preeclampsia Abnormal fetal testing
Diabetes mellitus Rh incompatibility
Heart disease Fetal abnormality
Prolonged pregnancy Premature rupture of membrane
IUGR chorioamnionitis
Indication of Augmentation
Abnormal labour( in presence of inadequate uterine contraction.
Prolonged latent phase
Prolonged active phase
Obstetrics Dr. Eman
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Contraindication of induction& augmentation
Maternal Fetoplacental
Absolute:
1.Contracted pelvis 1. Preterm fetus without lung maturity
2.Classical Caesarean
Relative: 2. Acute fetal distress
-Prior uterine surgery 3. Abnormal presentation
-Complete transection of uterus (myomectomy)
-Overdistented uterus
What it should be done when IOL is decided
Before IOL : Blood group &crossmatch.
During IOL: continuous electronic monitoring of fetal heart rate & uterine
activity is required. An internal uterine catheter for monitoring uterine pressure
is required during induction
Methods of IOL
Local application of PG:
prostaglandin E2: gel form is available is for an intracervical application of
dinoprostone. which can be removed quickly if the medication cause
hyperstimulation.
prostaglandin E2: the gel form is available in a 2.5-mL syringe
for an intra-cervical application of 0.5 mg of dinoprostone, which can be
removed quickly if the medication cause hyper stimulation. )(
The gel is deposited just below the internal cervical os. After application she
remains reclined for at least 30 minutes. Doses may be repeated every 6 hours,
with a maximum of three doses recommended in 24 hours.
Cytotec (misopristol) is a synthetic PG E1 can be used in a dose 25 Mg tablet
placed intravaginally
dinoprostone(PG E1) 10 mg vaginal insert is also approved for cervical ripening.
This is a thin, flat, rectangular held within a small, white sac. The sac has a long
attached tail to allow easy removal from the vagina.
Obstetrics Dr. Eman
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Intrauterine placement of catheter
Use of osmotic dilator
All above can cause cervical ripening
Artificial rupture of membrane (ARM):
increase uterine contraction
Membrane Stripping for Labor Induction
---stripping is safe and decreased the incidence of postterm gestation.
---significantly increased serum levels of endogenous prostaglandins.
---stripping cause spontaneous labor within 72.
---The incidence of ruptured membranes, infection, and bleeding was not increased.
Oxytocin :
can initiate effective uterine contraction & is only drug approved for induction &
augmentation. Oxytocin is identical to natural pituitary peptide.
pitocin is a synthetic preparation
Obstetrics Dr. Eman
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Bishop score
It is helpful to assess the likelihood of success by pelvic examination to
determine Bishope score, which evaluate status of cervix and station of fetal
head.A score of 9-13 is associated with high likelihood of vaginal delivery , a
score of less than 5 is associated with decreased likelihood of success.
Obstetrics Dr. Eman
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Oxytocin must be given intravenously to allow it to be discontinued if a
complication such as uterine hypertonus or fetal distress develops.
Because oxytocin has a half life of 3-5 minutes its physiological effect will
decrease in 15-30 minutes.
A dilute infusion must be used into IV line.
Infusion is best given by infusion pump.
Induction of labour should not exceed 72 hr. In patient with a low bishop
score, labour may progress slowly . If cx effaces & dilate, it is
recommended that membrane can be ruptured on 3rd day. If adequate
progress within 12 hr of rupturing the membrane, CS can be performed.
if adequate labour is established, infusion rate can be reduced, especially
during 2nd stage of labour . This approach avoid the risk of
hyperstimulation& fetal distress.
Method of oxytocin infusion for induction or augmentation.
Solution----
10 units of oxytocin in 1000 ml of 5% dextrose or salt solution.
Administraion
Into iv line , administer solution by infusion pump.
Obstetrics Dr. Eman
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Complication of IOL
1. Uterine hyperstimulation& cause fetal distress due to ischemia. Tetanic
contraction & lead to uterine rupture.
2. Oxytocin has antidiuretic effect , increase water reabsorption from
glomerular filtrate. Severe water intoxication with convulsion & coma can
occur when oxytocin is infused continuously more than 24 hr.
Complication
Prolonged infusion of oxytocin can result in uterine muscle fatigue &post
delivery uterine atony which increase risk of postpartum haemorrhage
Uterine tachysystole is defined as 6 contractions in a 10-minute period.
Uterine hypertonusis described as a single contraction lasting longer than
2 minutes.
Uterine hyperstimulation is when either condition leads to a
nonreassuring fetal heart rate pattern.
IOL before term is indicated only when the continuation of pregnancy
represent significant risk to fetus or mother.
At term , induction is indicated in the case of premature rupture of
membrane PROM, in patient with history of precipitous delivery(less than
3 hr) or lives an unusually long distance from hospital
Castor oil, bath, and/or enema
It has been shown that castor oil is associated with meconium passage possibly
by a direct effect on the fetal bowel.